Hi. I wanted to know if it's needed to install a firewall on a linux desktop/laptop. Why yes or why no?
On a laptop absolutely. My firewall on my laptop doesn't let me discriminate between networks so I'm always worried someone will try to attack me on public WiFi for the few ports I want open
On a desktop on a network you trust less important but still no firewall means if another device on your network gets compromised you're screwed
Ironically enough if you do not know what a firewall actually does (and saying it "protects" against "stuff is NOT enough) IMHO you do need one. That being said unless you know what you are doing, better leave it to the default one with default settings.
Very few people do, you probably don't need to worry about it
Yes, because you can forget what services are running and maybe they can be explited.
An example can be Syncthing which setting are done via web browser at port 8384. If you do not have a firewall, everyone on the same network would be able to change Syncthing settings and then sync your directories to their devices.
Is syncthing listening on all addresses, or only loopback? A firewall would block it, sure, but that would also be bad design.
I still don't know what a firewall actually does lol. I just install nftables and ufw and hope it somehow improves my security. I just don't know how.
